Both these distinguished American officers were reminded, as indeed they must have seen for themselves, that the successful combating of the submarine danger depended largely on the manufacture of material, and that the resources of this country, with its great fleet and its large and increasing armies, were so seriously taxed that the execution of the plans of the Admiralty were being constantly and gravely delayed. The Admiralty was, indeed, seriously embarrassed by difficulties in the adequate supply of mines and other means of destroying submarines as well as of fast craft of various descriptions. The Admiralty, as was pointed out, were doing not what they would like to do, but what they could do, both in the way of offensive and defensive action. The supplies of raw material and labour controlled in large measure the character and extent of the operations at sea. CHAPTER VII PATROL CRAFT AND MINESWEEPING SERVICES It is difficult to give an idea of the truly magnificent work achieved by the patrol and minesweeping services during the year 1917 without showing how these services expanded after the outbreak of war in 1914. When war was declared the only vessels immediately available for the work consisted of seven torpedo gunboats manned by officers and men of the Royal Navy, and fourteen trawlers manned by fishermen. All these vessels were fitted for regular minesweeping work, and the crews of the trawlers formed a part of what was known as the "Trawler Reserve." Other trawlers, exceeding eighty in number, became, however, almost immediately available at the outbreak of war under the organized Trawler Reserve which had been set up a year or two preceding the outbreak of war. Men belonging to this reserve had been trained in the work of minesweeping and were paid a small retaining fee. As soon as the German methods of indiscriminate minelaying and submarine attacks upon merchant ships commenced, a great expansion of this force became necessary. The matter was handled energetically by the Admiralty at the time, and by the end of 1914 over 700 vessels (yachts, trawlers and drifters) were employed on patrol and minesweeping duties, and the Admiralty had also commenced to build vessels of the trawler type specially for this work. By the commencement of 1917 there were in use some 2,500 yachts, trawlers and drifters, the great majority of them manned by fishermen or men of the R.N.R. or R.N.V.R. and officered by trawler or drifter skippers or officers of the R.N.R. or R.N.V.R., many of them having temporary commissions in these services. Early in the war the coast of the United Kingdom had been divided into areas for purposes of patrol and minesweeping, and each area was under the command of a naval officer on either the active or retired list.